BackgroundAdiposity has been linked to both higher risk of asthma and reduced lung function. The effects of adiposity on asthma may depend on both atopic status and gender, while the relationship is less clear with respect to lung function. This study aimed to explore longitudinal weight changes to changes in forced expiratory volume in first second FEV1 and forced vital capacity FVC, as well as to incident cases of asthma and wheezing, according to atopy and gender.

MethodsA general population sample aged 19–72 years was examined with the same methodology five years apart. Longitudinal changes in weight, body mass index, waist circumference, and fat percentage bio-impedance were analyzed with respect to changes of FEV1 and FVC spirometry, and incidence of asthma and wheezing questionnaire. Gender, atopy serum specific IgE-positivity to inhalant allergens and adipose tissue mass prior to adiposity changes were examined as potential effect modifiers.

ResultsA total of 2,308 persons participated in both baseline and five-year follow-up examinations. Over the entire span of adiposity changes, adiposity gain was associated with decreasing levels of lung function, whereas adiposity loss was associated with increasing levels of lung function. All associations were dependent on gender p-interactions ConclusionsOver a five-year period, increasing adiposity was associated with decreasing lung function, whereas decreasing adiposity was associated with increasing lung function. This effect was significantly greater in males than in females and increased with pre-existing adiposity, but was independent of atopy.